JPS5856494A - Method of forming art work film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an artwork film, and in particular, to eliminate deformation of landing caused by misalignment between an artwork original plate for baking a surface layer circuit pattern and a through-hole portion of a printed board to be applied. This invention relates to a method of forming an artwork film.

In recent years, multilayer printed circuit boards for mounting unit circuits, etc., are mounting a large number of individual components or LSI elements, etc.
As circuits wired within substrates become denser, circuit conductors become thinner, and the basic lattice spacing of through-holes that form interlayer connections, or the pitch between holes, becomes narrower.Under these circumstances, In the production of multilayer printed circuit boards, for example, drilling holes for forming through holes requires positioning of holes with high dust, and the drilled target board (glass cloth base material epoxy resin phosphorus) Strict relative positioning accuracy is required with respect to the artwork original plate on which the surface layer circuit pattern is printed onto the laminate board, etc.).

The present invention provides a means for forming a circuit pattern film that does not generate deformation force of land ring at the through-hole position in the production of printed circuit boards that require the above-mentioned relative alignment of 8 degrees. Problems encountered during firing of such a circuit pattern will be explained with reference to FIG.

In the same figure (a), 1 is a printed circuit board to be processed, 2
The through-holes 3 provided in the substrate 1 are processing reference holes, which are drilled in the first processing step of the substrate, regardless of whether it is an intermediate layer or a surface layer of a multi-layer stack, and then electroless copper plating, and then The front and back conductor circuits are connected to the inner wall surface of the hole 2 by electrolytic copper plating. After that, the circuit conductor pattern 4 or 4' shown in the figure is generated.The circuit conductor pattern 4.4' etc. is generated by pattern printing using screen printing technique and photoetching technique. The short-circuit part between the hole formation 2 and the connection corresponding part 5 such as the circuit conductor pattern 41 is a conductive circuit part with a land surface formed as shown in an enlarged view in FIG. Ensures soldering and fixation with the lead wire terminal inserted into the hole.

However, there is no relative positioning reference hole 3 between the artwork original plate for firing the surface layer circuit conductor pattern 4 and the printed circuit board for hole drilling, and this does not function effectively, for example, to improve the accuracy of drilling machine processing. Due to deformation of the printed circuit board itself, etc., misalignment occurs between the two, and the centers of the many land surfaces 5 provided in the circuit board and the through holes 2 do not match, resulting in land ring deformation 6 shown at the bottom of the enlarged view, and the holes are distorted. The purpose of the present invention is to eliminate the above-mentioned disadvantages, which makes it difficult to manufacture printed circuit boards with a strict temperature of 100 nm.

Therefore, according to the present invention, a circuit pattern film with a through-hole land pattern corrected is formed from a film in which hole positions are transferred from a hole-perforated printed board and a surface layer artwork original plate, and a surface layer circuit pattern is fired. This is a method of forming a workpiece film.

This will be explained below with reference to FIGS. 2 and 3 showing embodiments of the present invention.

In FIG. 2, 7 is a drilled substrate to be processed;
Reference numeral 8 denotes a film for creating reference holes for punching and hole position transfer together with the substrate 7, and the film 8 is made of a black (light-opaque) plastic sheet. That is, the upper part of the figure is the initial stage film of forming the circuit pattern film of the present invention, which is a printed circuit board 70 where the positions of holes 2 are transferred. This is a reference hole.

According to the present invention, the film 8 is then again drilled with a drill machining machine to form a hole 12 corresponding to the land diameter, that is, a hole corresponding to the land surface 5 in FIG. 1, to form the film 9. Hole 12
The diameter of the through-hole 2 is determined by the separately standardized surface layer land diameter designation.

Next, a light-transmitting black-and-white inverse film 10 is formed based on the perforated film 9.

As a result, a film 10 was obtained in which the through holes 2 of the substrate 7 to be processed were accurately positioned. The present invention includes such a film 10 and a surface layer artwork original (
The key point is to overlay and print the film 11 to form a circuit pattern that corrects the positional shift of the land pattern of the surface layer artwork original.

^ In the explanation in Section 11, in creating the film 8 in which reference holes for hole position transfer are formed, the substrate to be processed is used for drilling, but this also means that hole position transfer can be performed even from a substrate laminated with appropriate layers. It is also possible to create a film 10 and obtain a circuit pattern from which the positional deviation of the land pattern of the surface layer artwork original is corrected.

If the surface layer circuit pattern is fired using such a corrected circuit pattern, there will be no deformation of the randling.

FIG. 3 is a diagram showing another example of collection T+Ii of the present invention.

In such an embodiment, when baking the surface layer circuit pattern,
In order to improve the conventional drawback that the reference hole for relative positioning of the artwork original plate to the processing board does not function particularly effectively, and to minimize the deformation caused by the land ring due to the land position misalignment, the mounting reference hole is will be established.

That is, since the printed circuit board reference hole 3 expands and contracts and the artwork original 11 does not come into close contact with the board 7, a mounting reference hole, for example 13, separate from the reference hole 3 is provided.

When forming holes in the printed circuit board 7, a plurality of such mounting reference holes 13 are drilled at the periphery and central side of the surface layer artwork original 11. In this case, select the place where the surface layer artwork original plate and the through hole (the through hole is not shown) are closest to each other, and attach the mounting pin to the substrate 7 and the original plate 1.
1 is fixed, the deformation of the land ring (see Figure 1) can be minimized.

The method for forming an artwork film of the present invention as explained in the first embodiment has the advantage that high-precision surface layer circuit patterns, which are recently produced, can be fired very easily.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a state during firing of a conventional circuit pattern, and FIG. 8142 and FIG. 3 are a perspective view and a plan view showing an embodiment of the present invention. In the figure, 2 is a through hole, 3 is a reference hole, and 6 is a land surface 5.
deformation (landing deformation) part, 1 and 7 are printed circuit boards to be processed, 8, 9 and 10 are films according to the present invention with hole 2 position transfer, 11 is a surface layer artwork original, and 13 is a mounting reference hole. . Figure 1 Ivy 2 Figure '5 Continuation of figure 1 Page 0 Author: Keiji Kurosawa Inside Fujitsu Limited, 1015 Kamiodanaka, Nakahara-ku, Kawasaki City 0 Author: Mitsuo Yamashita Inside Fujitsu Limited, 1015 Kamiodanaka, Nakahara-ku, Kawasaki City

Claims (2)

[Claims] (1) When stacking the one-layer artwork original and the printed circuit board on which through-holes and reference holes are to be processed and firing the surface-layer circuit pattern on the substrate, the hole positions are determined from the side of the printed substrate to be applied. Step 4: Form a circuit (surface layer circuit by forming a turn film) by correcting the through-hole land pattern from the transferred film and the surface layer artwork original. - A method of forming a microscopic artwork film. (2) When drilling the through-holes and reference holes in the printed circuit board, a number of holes are drilled around the periphery of the surface layer artwork original plate to serve as mounting reference holes when forming the surface layer circuit pattern. A method for forming an artwork film according to claim 1.